SUMMARY
Azure disks deploy in an offline state
ISSUE
The reason you can not see the attached data disks in your deployed VM maybe caused by the Storage Area Network (SAN) policy set for your operating system. If you set the SAN policy to 'Offline Shared' before or you are using operating systems such as Windows Server 2012 and Windows Server 2012 R2 whose default SAN policy is 'Offline Shared', the attached data disks will not be mounted automatically after the VM is launched.
RESOLUTION
Follow this KB to set the SAN policy before replication to prevent this issue.
The following instructions will resolve the issue if san policy is not set correctly before deployment:
You can follow the steps to mount the offline disks:
For Windows Server 2012 and Windows Server 2012 R2:
Connect to your deployed instance.
- Click 'Start' menu
- Click 'Server Manager'.
- .

- In Server Manager Dashboard, Click 'File and Storage Services'.

- Click 'Disks'. Find the Offline disk, right click on it. Click 'Bring Online'.


For Windows Server 2008 and Windows Server 2008 R2:
- Connect to your deployed instance.
- Click 'Start' menu, then click 'Administrative Tools' and select 'Server Manager'.
- Click 'Storage', then 'Disk Management'. Find the Offline disk, right click on it and select 'Online'.


Now you can find the attached disks.